Cyclone Dovi / TC Dovi

11th Feb 2022 08:30 pm

Issued: 8:31pm Fri 11 Feb

 WARNINGS IN FORCE:

This warning cancels and replaces warning 087.

12th Feb 2022 01:00pm

Overnight TC Dovi has commenced it's transition to a Subtropical low. When this happens energy that is mostly concentrated at the centre of the system then gets distributed towards the outside of the system. How that energy gets distributed then determines it's impact going forward. Transition is often initiated by shearing - a process where the top of the cyclone moves away from it's centre. Additionally cooler waters kick off the transition process and Dovi has encountered this as it has moved further south. Sea temperatures need to be around 27C for tropical cyclones to form, and be sustained. Tropical Cyclone Dovi is currently above sea temperatures of around 24C.

The following graphic shows the path history and predicted path for the system (source: Earth Zoom)

Although when it reaches New Zealand, this system will be a sub tropical low (or Cyclone Dovi), it's still going to pack a punch. Looking at track paths is interesting and gives a general nature of where a storm is headed. However many cyclones including Dovi have long reaching impacts well outside the core system itself. For example in the graphic above you can see the significant rainfall that is on the South East section of the cyclone. There are strong winds on all other sides, that will still be around 100kph when the system hits the North Island. Wave heights of around 7m have been observed in the ocean, and there is likely to be heavy swells as the storm approaches the country.  There are Orange watches for rainfall and wind across the North Island and top of the South Island. Please follow these on the Metservice website and take action if necessary.

The tropical cyclone track map issued by Metservice this morning has suggested a slight movement north of the predicted path. The area of uncertainty of the track now includes Auckland. As transition is still occuring there is still much uncertainty around where the major impacts will be felt, as this will depend on where the energy ends up being distributed on the outer areas of the system. We'll update this later in the day where part of that information will be better known.

12th Feb 2022 11:00pm

We've left our update to late tonight, to ensure we have the latest information. Tomorrow (Sunday) looks like it's going to be the day it all happens. As expected Dovi has now transitioned to an ex Tropical Cyclone (Cyclone Dovi). The centre of the storm currently sits about 500kms NW of New Plymouth

Track Map

Cyclone Dovi has a central pressure of 982mb. As it moves across the central North Island the central pressure is expected to increase to 984mb 

Wind

As the storm crosses the central North Island, you will notice that there isn't significant wind in the centre of the cyclone. This is because the energy has been distributed away from the centre. There are two things to note. Firstly Auckland will see strong Northerlies with an average high of around 70 kmh with gusts over 100kmh.  For Auckland it's all over pretty quickly with winds reducing from about mid afternoon onwards.

For Wellington, average southerly winds of up to 50kmh and gusts up to 90kmh are expected, however strong winds are likely to stick around into Monday.

These wind strengths have the ability to cause power cuts and other damage.

Rain

As we've seen over the last few days the heavy rainfall in this system sits to the South and South East of the centre of the cyclone. There is plenty of rain about across the Norht Island in particular, but the heavy rain is focussed on the lower North Island and the upper South Island. Totals shown on the video below are for Wellington and are 3 hour totals.

It is intereseting to note that the GFS model is currently predicting more heavier rainfall over a wider area, slightly further south than the ECMWF modlel is predicting below.

 So plenty to watch over the next 24 hours. We'll be back in the morning with the first set of updates.

13th February 1:30 pm

Cyclone Dovi made "landfall" in New Zealand just after 10:30am, but as promised it has had significant impact in the last few hours. There are a number of power cuts, especially in the Auckland and Northland regions, flooding and slips, around the Lower North Island, along with many road closures. Kelburn has seen it's second wettest day on record (that's in nearly 100 years!), The Newshub article Weather live updates: NZ lashed with heavy rain and winds from Cyclone Dovi - what you need to know  provides a great summary.

The centre of the storm now lies just south of Hamilton, but it's still in Auckland and Wellington where all the action is. Here's a look at the storm at around 10am this morning as it is about to move onto land. The storm centre in quite clear, sitting north of New Plymouth

Wind

The good news is that it's all going to be over in a few hours. From the image below you can see there is a large high to the west of the country and this will move Cyclone Dovi off to the east of the North Island. There will be a brief period of strong winds down the North Islands east coast for a few hours this afternoon, but conditions in both Auckland and Wellington are easing from about now

 Rainfall

Rain will continue to fall in Wellington until Monday, although this won't be heavy as it has been. Wellington region is expecting another 40mm over the next 12 hours. Theres' also expected to be significant rainfall around the Kaikoura coast, and up towards Marlborough, with up to another 60mm of rain in the next 12 hours. Hamner Springs should see another 45mm.

Mount Taranaki is currently seeing heavy rain but this won't last too much longer. Much of the rest of the country should see only small amounts of rain. For most Monday will be clean up day!

The image below shows predicted rainfall at 3pm today as the high pressure moves in from the east, this will get pushed out towards the west.

Surface Analysis

The surface analysis map as at 1 am this morning is as follows (Metservice.com):

and the one from 7am this morning:

It's easy to see how complex this system is!